<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    // 1.普通类型
    let num1 = 1;
    let num2 = num1;
    num1 = 2;
    console.log(num1,num2) // 2 1

    // 2.引用类型
    let obj1 = new Object()
    let obj2 = obj1;
    obj1.name = 'Jack'
    console.log(obj2.name) // Jack
</script>
</body>
</html>